International Standards for Phytosanitary Measures, Publication 15, also known as ISPM 15, is a global guide which focuses on the treatment specifications for raw timbers as it relates to destroying all insects living within the material. All materials used by Top Box Inc. are heat-treated to reach a minimum temperature of fifty-six (56) degrees celsius at their core for a minimum of thirty (30) minutes.  An HT stamp is then placed on the materials. Top Box Inc. is certified to apply the ISPM 15 mark on all products they manufacture, a right granted to them by Timber Product Inspections of Atlanta, Georgia.